Abstract: A filling plug for battery cells includes a cylindrical housing, a valve system contained in the housing and connected to at least two horizontally protruding feeding tubes. Further, the filling plug includes a float partially projecting downward from the lower portion of the housing for actuating the valve system, and an axially extending tubular snap ring element which is to be inserted into and fastened in a filling opening of the battery cell. The snap ring element has bayonet coupling elements at an outer wall.

Abstract: A device that serves to automatically fill battery cells with water includes a filler plug that can be placed in the cell. The plug has two connection members for the water supply as well as a valve operated by a float. The valve body is connected in articulated fashion to the float, which is arranged centrally in the plug housing, via a pivotally mounted amplifying lever. Between the valve with the valve body and the connection member there is a substantially vertical overflow wall with a free upper edge that is higher than the horizontal upper edge of the bore of the connection members so that a U-shaped feed duct is formed that leads to the overflow wall.